Method and apparatus for delivery of a tubular to a drilling apparatus

ABSTRACT

A method for delivering a tubular to a well centered drill axis includes rotating a transfer arm to which a tubular is secured about a first axis from a horizontal position to a vertical position at which a center of gravity of the transfer arm and the tubular is disposed above the first axis; and rotating an upper link of the transfer arm about a second axis while oppositely rotating a clamp support beam about a third axis from the vertical position toward the drilling apparatus while a lower link remains in the vertical position. In delivering the tubular to a drilling apparatus, a tubular supply apparatus controls the speed and acceleration of the tubular without having actuators thereof change between compression and tension states or between rotational states.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Aspects of the invention relate to delivery of a tubular to a drillingapparatus for vertical and/or slant drilling operations, and a methodand an apparatus therefor.

2. Description of the Related Art

Accurate and controlled delivery of lengths of drill pipe or tubulars toa drilling apparatus is difficult to attain. Methods and apparatuses forraising and lowering a transfer arm to deliver tubulars to a well centerdrilling axis have been devised. However, some such methods andapparatuses use clamps specific to a diameter of the tubular to alignthe tubular with the well center drilling axis. Other methods andapparatuses used for raising and lowering a transfer arm in a drillingapparatus use a rigid, pivotably-mounted arm mounted adjacent to thedrilling mast or mounted at a short offset from the drilling mast. Suchmethods and apparatuses limit the accessibility of the area in front ofthe mast. Access at the front of mast is needed to allow installation,removal, and testing of well head equipment, such as a blow out prevent.

Further, other methods and apparatuses offset the mounting point of thetransfer arm on the transfer arm skid. Such arrangements result indifficult control of the deceleration and velocity of the transfer armas it approaches the upper position as such arrangements require acenter of gravity of the transfer arm to move over the pivot point ofthe transfer arm. When linear actuators are used to control the motionthereof, it is required that such linear actuators maintain control ofthe movement of the transfer arm while changing from compression membersto tension members. Alternately, when rotational actuators are used tocontrol the movement of the transfer arm, the rotational actuators mustchange states from driving to breaking. The switching of the states ofthe actuators is not easily controllable resulting in poor control ofthe movement of the transfer arm.

SUMMARY OF THE INVENTION

Aspects of the invention provide a transfer arm over which control ofthe speed and acceleration thereof as it nears the upper and lowerpositions is maintained. Aspects of the invention provide access andclearance around the front of the drill floor and drilling mast.

Aspects of the invention provide a method for delivering a tubular to adrill string, the method including: extending a lower actuator connectedbetween a lower link of a transfer arm and a transfer arm skid to raisethe transfer arm; and aligning the tubular with a well center drill axisof the drill string by compressing an upper actuator connected betweenan upper link of the transfer arm and the lower link while extending athird actuator connected between the upper link and a clamp support beamholding the tubular.

Aspects of the invention further provide a method of raising andlowering a transfer arm of a transfer arm skid to deliver a tubular to awell centered drill axis of a drilling apparatus, the method including:rotating a lower link, an upper link, and a clamp support beam of thetransfer arm about a first axis to align with an angle of the wellcentered drill axis, the lower link, the upper link, and the clampsupport beam being in a protracted state, and a proximate end of thelower link being pivotably connected to the transfer arm skid at thefirst axis; and rotating the upper link about a second axis whilerotating the clamp support beam about a third axis to align the tubularwith the well centered drill axis, a proximate end of the upper linkbeing pivotably connected to a distal end of the lower link at thesecond axis, and the clamp support beam being pivotably connected to adistal end of the upper link.

Aspects of the invention further provide a method of raising andlowering a transfer arm of a transfer arm skid to deliver a tubular to awell centered drill axis of a drilling apparatus, the method including:rotating a lower link, an upper link, and a clamp support beam of thetransfer arm about a first axis from a horizontal position to a verticalposition in which a center of gravity of the transfer arm is disposedabove the first axis; and rotating the upper link about a second axiswhile rotating the clamp support beam about a third axis from thevertical position toward the drilling apparatus while the lower linkremains in the vertical position.

Aspects of the invention further provide a tubular supply apparatus tosupply a tubular to a drilling apparatus, including: a transfer arm skidconnectable to a drilling apparatus; and a transfer arm, the transferarm including: a lower link rotatably connected to the transfer arm skidat a first axis, the lower link being rotatable about the first axis; anupper link rotatably connected to a distal end of the lower link at asecond axis, the upper link being rotatable about the second axis; aclamp support beam rotatably connected to a distal end of the upper linkat a third axis, the clamp support beam being rotatable about the thirdaxis and being connectable to a tubular.

Additional aspects and/or advantages of the invention will be set forthin part in the description which follows and, in part, will be obviousfrom the description, or may be learned by practice of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages of the invention will becomeapparent and more readily appreciated from the following description ofexemplary embodiments, taken in conjunction with the accompanyingdrawings of which:

FIG. 1 is a side elevational view of a drilling apparatus according toan exemplary embodiment of a tubular supply apparatus, showing thetransfer arm at a raised position;

FIG. 2 is side elevational view of the exemplary embodiment of FIG. 1,showing the transfer arm at an intermediate position;

FIG. 3 is side elevational view of the exemplary embodiment of FIG. 1,showing the transfer arm at a lower position;

FIG. 4 is an end elevational view of the exemplary embodiment of FIG. 3,showing an embodiment of the invention including a tubular storage andindexing system with the tubular positioned for loading into thetransfer arm and the transfer arm at a lowered position;

FIG. 5. is an end elevational view of the exemplary embodiment of FIG.3, showing the tubular storage and indexing system with the tubularpositioned for loading out of the transfer arm and the transfer arm at alowered position; and

FIG. 6 is a top plan view of the exemplary embodiment of FIG. 3, showingthe tubular storage and indexing system with the tubular positioned forloading into the transfer arm and the transfer arm at a loweredposition.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the exemplary embodiments of theinvention, examples of which are illustrated in the accompanyingdrawings, wherein like reference numerals refer to the like elementsthroughout. Exemplary embodiments are described below in order toexplain the invention by referring to the figures.

FIGS. 1 through 3 show a drilling apparatus 1 and a tubular supplyapparatus 30. The drilling apparatus 1 includes a drilling mast 2 and adrill floor 25. The drilling mast 2 is disposed in a generally verticalposition, but the orientation is not limited thereto. The tubular supplyapparatus 30 includes a transfer arm skid 4 that is disposed in agenerally horizontal position and is connectable to the drillingapparatus 1 via a reaction point 12. Each of the drilling apparatus 1and the tubular supply apparatus 30 may include wheels so as to bemoveable between drilling sites or may be fixed structures. Further, thetubular supply apparatus 30 may be connectable to the drilling apparatus1 via the reaction point 12 or may be fixed to the drilling apparatus 1.The transfer arm skid 4 may include a locking hydraulic cylinder 26 thatproperly places the transfer arm skid 4 with respect to the drillingapparatus 1. The locking hydraulic cylinder 26 may extend to level oradjust the height of the transfer arm skid 4 and may be locking suchthat when hydraulic fluid or pressure is removed therefrom, the lockinghydraulic cylinder 26 maintains the position to which it was extended.

The tubular supply apparatus 30 includes the transfer arm skid 4 and amoveable transfer arm 3. The transfer arm skid 4 provides support forthe transfer arm 3. The transfer arm skid 4 may further provide supportfor queue and storage for a plurality of tubulars 23, in a horizontalposition, to be transferred to the drilling apparatus 1. The transferarm skid 4 may include leveling jacks or hydraulic actuators (not shown)to adjust the skid height in both lengthwise and transverse directions.The transfer arm skid 4 may also include indexers to lift one of thetubulars 23 from a storage area to the transfer arm 3 and kickers tomove the tubular from the transfer arm 3 back to the storage area.

The transfer arm 3 includes three main sections: a lower link 8, anupper link 9, and a clamp support beam 10. The transfer arm 3 pivotsabout a first axis 5, which is fixed with respect to the mast 2, betweena generally horizontal position (lowered position), and a generallyvertical position (raised position). However, aspects of the inventionare not limited thereto such that the transfer arm may be rotated aboutthe first axis 5 to an inclined position (i.e., a position between thelowered position and the raised position). A proximate end 8 a of thelower link 8 is rotatably connected to the transfer arm skid 4 at thefirst axis 5 such that the lower link 8 pivots or rotates about thefirst axis 5 with respect to the transfer arm skid 4. Although the firstaxis 5 is shown in FIGS. 1 through 3 as being fixed with respect to thetransfer arm skid 4, aspects of the present invention are not limitedthereto such that the first axis 5 may be moveable along a length of thetransfer arm skid 4.

The upper link 9 pivots about a second axis 6. A proximate end 9 a ofthe upper link 9 is rotatably connected to a distal end 8 b of the lowerlink 8 at the second axis 6 such that the upper link 9 pivots or rotatesabout the second axis 6 with respect to the lower link 8. The clampsupport beam 10 is connected to a distal end 9 a of the upper link 9 ata third axis 7 such that the clamp support beam 10 pivots or rotatesabout the third axis 7. The clamp support beam 10 has a first end 10 aand a second end 10 b. The clamp support beam 10 is connected to thedistal end 9 b of the upper link 9 such that the first end 10 a iscloser to the third axis 7 than the second end 10 b of the clamp supportbeam 10 (i.e., the clamp support beam 10 may be connected to the distalend 9 b of the upper link 9 at a point one-fifth to one-third of thelength of the clamp support beam 10 from the first end 10 a of the clampsupport beam 10), but the invention is not limited thereto. Although theclamp support beam 10 is illustrated as being connected centrally, withrespect to a width or a diameter of the clamp support beam 10, to thedistal end 9 b of the upper link 9, aspects of the invention are notlimited thereto such that the clamp support beam 10 may further includea connected or connectable bracket or coupling. Further, the connectionof the clamp support beam 10 may be moveable along the length of theclamp support beam 10.

The clamp support beam 10 supports two grip assemblies 11, which areused to secure a tubular 23 to the transfer arm 3 when the transfer arm3 is used to raise and lower the tubular 23 between a drill or pipestring (not shown) and pipe storage outriggers 31 (shown in FIG. 4). Thetwo grip assemblies 11 are spaced apart from each other along a lengthof the clamp support beam 10. The grip assemblies 11 may secure tubulars23 of different diameters and lengths so as to allow positioning andalignment of such tubulars 23 with a well center drill axis. Althoughonly two grip assemblies 11 are shown in FIGS. 1-3, the clamp supportbeam 10 is not limited thereto such that more or fewer grip assemblies11 may be included. Further, the grip assemblies 11 may be moveablealong the length of the claim beam 10. The grip assemblies 11 mayinclude linkages actuated with hydraulic or rotational actuators.Further, the clamp support beam 10 may include tubular holders 11 a toaid in centering the tubulars 23 in the grip assemblies 11, and allowthe tubulars 23 to roll over clamp elements.

A lower actuator 14 (or raising, or first actuator) includes a first end15, which is pivotably connected to the transfer arm skid 4, and asecond end 16, which is pivotably mounted to the lower link 8. The loweractuator 14 is disposed between the transfer arm skid 4 and the lowerlink 8 to control the lower link 8 to move away from the transfer armskid 4 and raise the transfer arm 3 from the generally horizontalposition (shown in FIG. 3). The lower actuator 14 is connected to anupper side of the transfer arm skid 4 and connected to a lower side ofthe transfer arm 3 (i.e., a lower side of the lower link 8 when thetransfer arm 3 is disposed in the generally horizontal position). Thelower actuator 14 may be connected directly to the transfer arm skid 4and the lower link 8 or may be connected by an additional bracket orcoupling.

The lower actuator 14 may extend to raise the transfer arm 3 about thefirst axis 5 to an intermediate position shown in FIG. 2 from its lowerposition shown in FIG. 3. As shown in FIG. 2, the transfer arm 3 isdisposed directly above the first axis 5 in a protracted, generallyvertical position; therefore, the lower actuator 14 extends to raise thetransfer arm 3 to a point at which a center of gravity of the transferarm 3 is disposed above the first axis 5 about which the transfer arm 3pivots. In such a configuration, the lower actuator 14 controls themovement of the transfer arm 3 without changing states from acompression member to a tension member. The lower actuator 14 may movethe transfer arm 3 from the generally horizontal position, as shown inFIG. 3, to the generally vertical position, as shown in FIG. 1, andpositions therebetween. The lower actuator 14 may move the transfer arm3 to inclined positions (i.e., positions between the generallyhorizontal position and the generally vertical position), so as todeliver the tubular 23 to a slant drill apparatus of which the drillingmast 2 is not vertically oriented, however, delivery of the tubular 23to the slant drill apparatus is not limited to such. Specifically, thetransfer arm 3 may be raised to an inclined position to deliver thetubular 23 to the slant drill apparatus. When the transfer arm 3 is inthe generally horizontal position as shown in FIG. 3, the lower actuator14 is in a short or compressed state; and, when the transfer arm 3 is inthe generally vertical position as shown in FIGS. 1 and 2, the loweractuator 14 is in a long or extended state. When the transfer arm 3 isin an inclined position, the lower actuator 14 is in an intermediatestate between the compressed and extended states.

The lower actuator 14 may be a hydraulic cylinder or multiple hydrauliccylinders, but the invention is not limited thereto. In order to raisethe transfer arm 3, pressurized hydraulic fluid or air may be suppliedto the lower actuator 14. Further, when the first axis 5 is moveablealong the length of the transfer arm skid 4, the lower actuator 14 mayalso be moveable along the length of the transfer arm skid 4 (i.e., thefirst end 15 of the lower actuator 14 may be moveable in associationwith the first axis 5).

An upper actuator 17 (or rotation, or second actuator) includes a firstend 18, which is pivotably mounted to the lower link 8, and a second end19, which is pivotably mounted to the upper link 9. The first end 18 ofthe upper actuator 17 is connected to an upper side of the lower link 8and the second end 19 of the upper actuator 17 is connected to an upperside of the upper link 9 (i.e., the upper actuator 17 is connected toupper sides of the lower link 8 and the upper link 9 with respect to thetransfer arm 3 being disposed in the generally horizontal position asshown in FIG. 3). The upper actuator 17 is connected to an upper side ofthe transfer arm 3, which is opposite to the lower actuator 14 (i.e.,the upper actuator 17 and the lower actuator 14 are disposed on oppositesides of the transfer arm 3).

When the transfer arm 3 is in the generally horizontal position as shownin FIG. 3, the upper link 9 and the lower link 8 are generally parallel,and the transfer arm 3 is in a lengthened or protracted state. When thetransfer arm 3 is in the protracted state, the upper actuator 17 is in along or extended state. The upper actuator 17 contracts to a short orcompressed state to control the upper link 9 to rotate about the secondaxis 6 toward the drilling apparatus 1 such that the distal end 9 b ofthe upper link 9 extends beyond the first axis 5 to be disposed over thedrill floor 25 of the drilling apparatus 1.

When the upper actuator 17 is in the compressed state, the clamp supportbeam 10 is disposed over the drill floor 25 such that the tubular 23 maybe aligned with the drill string. As shown in FIG. 2, the transfer arm 3is disposed directly above the first axis 5 in a protracted, generallyvertical position; therefore, when the upper actuator 17 contracts tocontrol the rotation of the upper link 9 about the second axis 6 toextend the clamp support beam 10 over the drill floor 25, the upperactuator 17 controls the movement of the transfer arm 3 as a compressionmember and does not change between a compression state and a tensionstate when moving to extend the clamp support beam 10, or the distal end9 b of the upper link 9, toward the drilling apparatus 1 (i.e., fromFIG. 2 to FIG. 1).

The upper actuator 17 may be connected to the lower link 8 and the upperlink 9 directly or may be connected by an additional bracket or coupling(as shown in FIGS. 1 through 3). The upper actuator 17 may be ahydraulic cylinder or multiple hydraulic cylinders but is not limitedthereto.

A third actuator 20 includes a first end 21 which is pivotably mountedto the upper link 9, and a second end 22, which is pivotably mounted tothe clamp support beam 10. The third actuator 20 is connected to theupper side of the upper link 9 and connected to a lower side of theclamp support beam 10, upper and lower being defined with respect to thetransfer arm 3 being disposed in the generally horizontal position shownin FIG. 3. While not required in all aspects, the second end 22 of thethird actuator 20 is connected to the clamp support beam 10 between thefirst end 10 a of the clamp support beam 10 and the third axis 7. Thethird actuator 20 is disposed between the upper link 9 and the clampsupport beam 10 to control the first end 10 a of the clamp support beam10 to move away from the upper link 9 and move the clamp support beam 10to a generally vertical position to align with the drill string as shownin FIG. 1. When the third actuator 20 is in a compressed or short state,the clamp support beam 10 is generally parallel to the upper link 9 asshown in FIGS. 2 and 3. When the third actuator 20 is in an extended orlong state as shown in FIG. 1, the clamp support beam 10 is rotated withrespect to the upper link 9 such that first end 10 a of the clampsupport beam 10 is disposed away from the upper link 9. The clampsupport beam 10, lower link 8, and the upper link 9 are connected suchthat when the transfer arm 3 is disposed in the generally horizontalposition shown in FIG. 3, the first end 10 a of the clamp support beam10 is disposed closer to the drilling apparatus 1 than the second end 10b of the clamp support beam 10. Further, the third actuator 20 controlsthe clamp support beam 10 to move without changing states from a tensionto a compression state when moving the clamp support beam 10 over thedrill floor 25, or moving the clamp support beam 10 from the positionshown in FIG. 2 to the position shown in FIG. 1.

It should be understood that the lower link 8, the upper link 9, and theclamp support beam 10 may be exchanged for lower links 8, upper links 9,and clamp support beams 10, respectively, of different lengths so as toaccommodate different lengths of the tubulars 23, different sizes anddimensions of different drilling apparatuses 1, and different locationsof the drill string with respect to the first axis 5. For example, anupper link 9 having a greater length than shown in FIGS. 1 through 3 maybe included in the transfer arm 3 so as to allow for delivery of atubular 23 to a drilling apparatus 1 having a larger drilling platform.

It should be understood that the transfer arm 3 is suited for a widevariety of drilling devices and transfer arms. The drilling apparatus 1and the transfer arm 3 have been shown merely to define the environmentof this invention. Similarly the transfer arm 3 may be a stressed skin,a monocoque construction, a laminated fiber, or a cross-braced truss.The lower actuator 14, the upper actuator 17, and the third actuator 20may be a single set of hydraulic actuators, as shown in the drawings, ormay be multiplied in sets, identical or otherwise. For example, thelower actuator 14, the upper actuator 17, and the third actuator 20 maybe identical hydraulic actuators, having one of each disposed on eachside of the transfer arm 3. Similarly, the lower actuator 14, the upperactuator 17, and the third actuator 20 may be linear actuators or may berotational actuators disposed at axes 5, 6, 7 to provide similar motionof the lower link 8, the upper link 9, and the clamp support beam 10, ormay be combinations thereof. Further, the links on the transfer arm 3may be box-section structures with thick multi-plate fabrications toresist high stress. Moreover, it is understood that additional actuatorscan be used, such as actuators to control a rotation about an axisparallel to a length of the transfer arm 3 or to control the gripassemblies 11 to rotate about the clamp support beam 10 (i.e., to rotatethe tubular 23 about another horizontal axis or to be loaded with thetubular 23 from either side of the transfer arm skid 4).

Although illustrated and described as having only the lower link 8, theupper link 9, and the clamp support beam 10, aspects of the inventionare not limited thereto such that the transfer arm 3 may includeadditional links and actuators capable of aligning the tubular 23 withthe well center drilling axis while preventing the actuators fromchanging states between tension and compression (or forward and reverserotation) while the transfer arm 3 is being raised to deliver thetubular 23. For example, the upper link 9 may include two portionspivotably or rotatably connected that are rotated by control of anadditional actuator.

FIGS. 4 through 6 show a tubular storage and indexing system accordingto an embodiment of the invention. The tubular storage and indexingsystem delivers tubulars 23 to the transfer arm 3 according to an aspectof the invention. While shown with the transfer arm 3, it is understoodthat the invention is not limited thereto, and that the tubular storageand indexing system can be separately provided and can be used withother mechanisms which transfer tubulars 23 to the drilling apparatus 1.

A transfer arm skid 4 includes tubular storage outriggers 31, which areconnected to the transfer arm skid 4 by pivot blocks 40, and indexinglifting arms 33, which are connected to mounts 38 of the transfer armskid 4. The tubular storage outriggers 31 and the indexing lifting arms33 may be disposed on only one side of the transfer arm skid 4, suchthat the tubulars 23 may be delivered to the transfer arm 3 from onlyone side of the transfer arm skid 4, or on both sides of the transferarm skid 4, such that tubulars 23 may be delivered to the transfer arm 3from either or both sides of the transfer arm skid 4. The pivot blocks40 are disposed at one end of the tubular storage outriggers 31 torotatably or pivotably connect the tubular storage outriggers 31 to thetransfer arm skid 4. Further, the pivot blocks 40 may allow the tubularstorage outriggers 31 to pivot or rotate horizontally so that thetubular storage outriggers 31 are parallel to the transfer arm skid 4 tobe disposed in a stored position for transport or storage. The pivotblocks 40 are disposed on the transfer arm skid 4 below the grippingassemblies 11 disposed on the clamp support beam 10 so that the tubularstorage outriggers 31 are disposed at a small distance above the groundon which the transfer arm skid 4 rests.

The tubular storage outriggers 31 can be inclined towards or away fromthe transfer skid 4 by outrigger actuators 41 attached to the outer endof tubular storage outriggers 31 (i.e., an end of the tubular storageoutriggers 31 opposite the end connected to the transfer arm skid 4). Byrotating the tubular storage outriggers 31 about the pivot blocks 40 toinclined or declined positions, the tubular storage outriggers 31deliver or remove tubulars 23 from the transfer arm skid 4 in trip inand trip out operations, respectively. When the outrigger actuators 41are extended to incline the tubular storage outriggers 31 towards thetransfer skid 4 as shown in FIG. 4, the tubulars 23 are moved towardsthe transfer arm skid 4 to or are positioned to rest against adjustablepins 39. The adjustable pins 39 are positioned on the tubular storageoutriggers 31 for different diameters of the tubular 23 so that thetubular 23 is in a correct position to be picked up by indexing liftingarms 33. The adjustable pins 39 may be of different diameters or shapesor at different positions on the tubular storage outriggers 31 accordingto a diameter of the tubular 23 to be indexed.

The indexing lifting arms 33 are pivotally mounted to mounts 38 of thetransfer skid 4 at indexing axis 36. The indexing lifting arms 33 arepivotally rotated with respect to the transfer skid 4 by indexingactuators 35. The outer ends of each of the indexing lifting arms 33 areformed with an indexing finger 42 and an indexing edge 43, the outerends being the ends of the indexing lifting arms 33 disposed away fromthe indexing axis 36. When a tubular 23 is resting against theadjustable pin 39, the indexing lifting arms 33 are rotated about axis36 by the indexing actuators 35 upward from their full line position, aposition below the tubular 23 to be picked up, to the dashed lineposition, a position in which the tubular 23 rolls down the indexinglifting arms 33 toward the tubular holders 11 a, as shown in FIG. 4. Thetubular 23 is captured by the finger 42 and moved with indexing liftingarms 33 whereupon the tubular 23 rolls along the indexing lifting arm 33onto the gripping assemblies 11 (described above) and into recesses 44of the tubular holders 11 a where the tubular can be secured to thetransfer arm 3 by the gripping assemblies 11. The indexing edges 43 ofthe indexing lifting arms 33 prevent the awaiting tubular 23, or thenext tubular 23 to be picked up, from interfering with the motion of theindexing lifting arm 33 as well as queues the next tubular 23 for thenext transfer. Additional, retractable pins may be provided in thetubular holders 11 a to prevent the tubular 23 from rolling past therecesses 44 of the tubular holders 11 a. The tubulars 23 roll downsurfaces of the pipe storage outriggers 31 toward the transfer arm skid4, are then lifted by the indexing lifting arms 33 from a height of thepipe storage outriggers to a height at least slightly above the grippingassemblies 11, and then roll down surfaces of the indexing lifting arms33 to be delivered to the recesses 44 of the tubular holders 11 a of thetransfer arm 3. After delivery of the tubular 23 to the transfer arm 3,the indexing lifting arm 33 may be lowered to pick up the next tubular23 to be delivered to the transfer arm 3. As the indexing lifting arm 33is lowered, the next tubular 23 to be delivered to the transfer arm 3 isdisposed against the indexing edges 43 of the indexing lifting arms 33until the fingers 42 of the indexing lifting arms 33 are low enough thatthe next tubular 23 to be delivered to the transfer arm 3 rolls to restagainst the adjustable pins 39. The next tubular 23 to be delivered tothe transfer arm 3 is then ready to be picked up and delivered in themanner described above.

Each indexing lifting arm 33 houses a kicker assembly 37 used to returnthe tubular 23 to the pipe storage outriggers 31. The kicker assembly 37is disposed at the end of the indexing lifting arm 33 connected to theindexing axis 36 (i.e., the end opposite the indexing finger 42 and theindexing edge 43). The kicker assembly 37 is extendable from theconnected end of the indexing lifting arm 33. In order to remove atubular form the gripping assemblies 11 to a stored position on thetubular storage outriggers 31, the indexing lifting arm 33 is disposedin an upper position as shown in FIG. 5. The kicker assembly 37 isextended from the full line position to the dashed line position of FIG.5 to extend below the tubular 23 resting in the recesses 44 of thetubular holders 11 a. The indexing lifting arms 33 with the kickerassemblies 37 extended are then rotated about the indexing axisoppositely to the rotation of supplying a tubular 23 to the transfer arm3 as described above (i.e., the indexing lifting arms 33 are rotatedfrom a raised position to a lowered position). Upon lowering of theindexing lifting arms 33, the extended kicker assembly 37 lifts thetubular 23 to be delivered to the tubular storage outriggers 31 out ofthe recesses 44 of the tubular holders 11 a. The tubular 23 then rollsdown the surface of the indexing lifting arms 33 to rest against theindexing fingers 42 of the indexing lifting arms 33 as the indexinglifting arms 33 are lowered. The tubular 23 is then delivered back tothe tubular storage outriggers 31. The outrigger actuators 41 arecompressed or retracted such that the tubular storage outriggers 31 aredisposed in a declined position with respect to the transfer arm skid 4such that when the tubular 23 removed from the recesses 44 of thetubular holders 11 a is disposed on the tubular storage outriggers 31,the tubular 23 rolls along the surface of the tubular storage outriggers31 away from the transfer arm skid 4 to the outer ends of the tubularstorage outriggers 31 (i.e., ends of the tubular storage outriggers 31not connected to the pivot blocks 40).

Although not required in all aspects, the kicker assemblies 37 may bedisposed inside the indexing lifting arms 33 and may be attached by andextended and retracted by a linear actuator. Such linear actuator mayalso be disposed inside the indexing lifting arm 33. The linear actuatormay move the kicker assembly 37 into and out of the indexing lifting arm33. Further, the kicker assemblies 37 may include kicker fingersdisposed at distal ends thereof (i.e., ends of the kicker assemblies 37nearest the gripping assemblies 11 may include the kicker fingers) tohold the tubular while the kicker assemblies 37 are lifted and/or toprevent the tubular 23 to be removed from the recesses 44 of the tubularholders 11 a from rolling in a wrong way (i.e., toward an other side ofthe transfer arm 3 opposite the indexing lifting arms 33 being used toremove the tubular 23).

Operation of the transfer arm 3 to lift a tubular 23 to a desiredposition for delivery to a drill string will be described hereinafterwith respect to FIGS. 1 through 3. With reference to FIG. 3, thetransfer arm is in a lowered or generally horizontal position in whichthe lower actuator 14 is in a compressed state, the upper actuator 17 isin an extended state, and the third actuator is in a compressed state.In the lowered or generally horizontal position, the lower link 8, theupper link 9, and the clamp support beam 10 are connected as describedabove and are generally parallel with each other and generally parallelwith the transfer arm skid 4. At this position, the tubular 23 isloaded. By way of example, the tubular 23 can be loaded using the pipesupply outriggers 31 and the indexing lifting arms 33 as shown in FIG.4. However, other mechanisms can be used.

In order to raise the transfer arm 3 from the horizontal position ofFIG. 3, the lower actuator 14 extends to rotate the transfer arm 3 aboutthe first axis 5 to move the transfer arm 3 through inclined positionsto the intermediate position shown in FIG. 2. FIG. 2 shows anintermediate position appropriate for vertical drilling but aspects ofthe invention are not limited thereto. The lower actuator 14 may or maynot extend fully but extends sufficiently to align the tubular 23 withat least an angle of the drill string or the well center drilling axis.For example, as shown in FIG. 2, the lower actuator is extendedsufficiently to place the tubular 23 in a vertical position, which isappropriate for vertical drilling. Further, when the lower actuator 14extends to move the transfer arm 3 to position the tubular 23 in thevertical position, a center of gravity of the transfer arm 3 is disposedabove the first axis 5 such that the lower actuator 14 does not changefrom a compression to a tension state while controlling the transfer arm3 to move. In a slant drilling operation, the lower actuator 14 mayextend to an inclined position to align the tubular 23 with an angle ofthe slanted drill string. However, in either vertical or slant drilling,the tubular 23 is not yet aligned with a well center drilling axis ofthe drill string. As the lower actuator 14 extends, the transfer arm 3is raised as a rigid unit (i.e., the upper actuator 17 remains in theextended state and the third actuator 20 remains in the compressed statesimilar to when the transfer arm 3 is in the generally horizontalposition). While described as lifted as a rigid unit, it is understoodthat slight movement between the lower link 8, the upper link 9, and theclamp support beam 10 can occur and the lower link 8, the upper link 9,and the clamp support beam 10 need not be substantially parallel in allaspects so long as the center of gravity for the transfer arm 3 does notextend beyond the first axis 5 while the transfer arm 3 is being liftedand/or the lower actuator 14, the upper actuator 17, and the thirdactuator 20 do not change states between compression states and tensionsstates.

Upon alignment of the tubular 23 with the angle of the drill string, thelower actuator 14 stops extending so as to maintain such alignment.Then, to move from the intermediate position of FIG. 2 to the verticalposition of FIG. 1, the upper actuator 17 begins to retract to acompressed state while the third actuator 20 begins to extend to anextended state such that the upper link 9 is rotated about the secondaxis 6 toward the drilling apparatus 1 while the clamp support beam 10is rotated in an opposite direction about the third axis 7. The distalend 9 b of the upper link 9 is rotated toward the drilling apparatus 1,and the first end 10 a of the clamp support beam 10 is rotated towardthe drilling apparatus 1 and away from the upper link 9. The upperactuator 17 retracts and the third actuator 20 extends such that thetubular 23 maintains alignment with the angle of the drill string untilthe tubular 23 is aligned with the well center drilling axis of thedrill string. Upon alignment of the tubular 23 with the well centerdrilling axis of the drill string, the tubular 23 may then be deliveredto the drill string as the grip assemblies 11 are released. Further, arate at which the transfer arm 3 is controlled to raise the tubular 23may be dependent upon a size and/or a weight of the tubular 23, may beautomatic, and/or may be manually controlled. Further, the indexing andkicking related to the gripper assemblies 11 and a position of thetransfer arm 3 may be automatic, and/or may be manually controlled.

For vertical drilling, the lower actuator 14 is extended to place thetubular 23 and the transfer arm 3 in a generally vertical position asshown in FIG. 2 such that the lower actuator 14 does not change statesfrom a compression to a tension state while moving the transfer arm 3.Then, the upper actuator 17 retracts and the third actuator 20 extendswhile maintaining the tubular 23 in a generally vertical position, toalign the tubular 23 with the vertical drill string while the loweractuator 14 remains fixed (i.e., not extending or retracting). The upperactuator 17 retracts and the third actuator 20 extends until thetransfer arm 3 is in the raised position shown in FIG. 1. Even when thetransfer arm 3 approaches the raised position of FIG. 1, the angularorientation of the upper actuator 17 is such that it provides excellentcontrol over acceleration and velocity of the transfer arm 3. As such,precise, high speed, fully-automated control of the position of thetransfer arm 3 and tubular 23 is possible.

For slant drilling, the tubular supply apparatus 30 may be arrangedabout a slanted drill string such that the slanted drill string extendsinto the ground beneath the tubular supply apparatus 30. In such case,the lower actuator 14 is extended to place the tubular 23 and thetransfer arm 3 in a generally vertical position as shown in FIG. 2 suchthat the lower actuator 14 does not change states from a compression toa tension state while moving the transfer arm 3. Then, the upperactuator 17 retracts and the third actuator 20 extends, respectively, toalign the tubular 23 with a well center drilling axis of the slanteddrill string. The upper actuator 17 retracts and the third actuator 20extends until the transfer arm 3 is in an inclined position beyond thefirst axis 5 sufficient to deliver the tubular 23 to the slanted drillstring (i.e., the upper link 9 is extended beyond the first axis 5 suchthat the distal end 9 b of the upper link 9 and the clamp support beam10 are disposed to an opposite side of the first axis 5 from thetransfer arm skid 4). By way of example, the tubular 23 may be deliveredto a slanted drill string having an angle of about 20° with respect tothe ground.

The upper actuator 17 and the third actuator 20 may operatesimultaneously, but aspects are not limited thereto such that the upperactuator 17 may retract first, then the third actuator 20 may extend toalign the tubular 23 with the slanted drill string, or the thirdactuator 20 may first extend to a position such that when the upperactuator 17 is appropriately retracted, the tubular 23 is aligned withthe slanted drill string.

Further, although the upper actuator 17 and the third actuator 20 aredescribed as operating independently and simultaneously, aspects are notlimited thereto such that either the upper actuator 17 or the thirdactuator 20 may be operated before the other of the upper actuator 17and the third actuator 20 so as to operate independently and notsimultaneously. Moreover, the upper actuator 17 and the third actuator20 may be connected (i.e., share compression fluid) so as to operatesimultaneously and not independently. The upper actuator 17 and thethird actuator 20 may be connected via a dummy cylinder so as totransfer compression fluid therebetween. Thus, fluid or compressionremoved or added from one actuator is transfer to the other such thatthe movements thereof are calibrated and the upper link 9 and the clampsupport beam 10 are appropriately rotated about the second axis 6 andthe third axis 7, respectively, to align the tubular 23 with the drillstring.

To lower the transfer arm 3, from either the vertically raised positionor the slanted raised position, the upper actuator 17 extends and thethird actuator 20 retracts until the transfer arm 3 is disposed in thelengthened or protracted state such that the clamp support beam 10 andthe upper link 9 are generally parallel. Then, the lower actuator 14retracts to the compressed state such that the transfer arm 3 is in thegenerally horizontal position shown in FIG. 3. The transfer arm 3 isthen ready to deliver another tubular 23 to the drill string. Further, arate at which the transfer arm 3 is controlled to lower the tubular 23may be dependent upon a size and/or a weight of the tubular 23. Suchmethod of operation allows the transfer arm 3 to be raised and loweredwithout changing states of actuators therein between compression andtension states. However, aspects of the invention are not limitedthereto such that the lower actuator 14, the upper actuator 17, and thethird actuator 20 may simultaneously compress, extend, and compress,respectively, to lower the transfer arm 3 to the generally horizontalposition.

While not required in all aspects, the lower actuator 14, the upperactuator 17, and the third actuator 20 can be controlled manually orusing a computer controller. As such, aspects of the method can beimplemented using software and/or firmware executed using one or moreprocessors. Further, the tubular supply apparatus may include ananti-collision system by which collisions between a loaded tubular orthe transfer arm and the drilling apparatus, or other structure, areprevented.

Although a few exemplary embodiments of the invention have been shownand described, it would be appreciated by those skilled in the art thatchanges might be made in such embodiments without departing from theprinciples and spirit of the invention, the scope of which is defined inthe following claims and their equivalents.

1. A tubular supply apparatus to supply a tubular to a drillingapparatus, the tubular supply apparatus comprising: a transfer arm skidconnectable to the drilling apparatus; and a transfer arm whichtransfers the tubular with respect to the drilling apparatus, thetransfer arm comprising: a lower link rotatably connected to thetransfer arm skid at a first axis, the lower link being rotatable aboutthe first axis to rotate the transfer arm about the first axis; an upperlink rotatably connected to a distal end of the lower link at a secondaxis, the upper link being rotatable about the second axis; a clampsupport beam rotatably connected to a distal end of the upper link at athird axis, the clamp support beam being rotatable about the third axisand being connectable to the tubular.
 2. The tubular supply apparatus ofclaim 1, wherein the transfer arm skid further comprises: pivot blocksdisposed at a side of the transfer arm skid; and pipe storage outriggersrotatably connected to the pivot blocks to support the tubular thereon.3. The tubular supply apparatus of claim 2, wherein the transfer armskid further comprises: outrigger actuators connected to outside ends ofthe pipe storage outriggers opposite ends of the pipe storage outriggersconnected to the pivot blocks, the outrigger actuators to raise andlower the outside ends of the pipe storage outriggers with respect tothe ends of the pipe storage outriggers connected to the pivot blocks.4. The tubular supply apparatus of claim 2, wherein the transfer armskid further comprises: mounts disposed on the transfer arm skid belowthe transfer arm when the transfer arm is disposed in a generallyhorizontal position; and indexing lifting arms rotatably connected tothe mounts, the indexing lifting arms to lift the tubular supported bythe pipe storage outriggers from the pipe storage outriggers to theclamp support beam.
 5. The tubular supply apparatus of claim 4, whereinthe indexing lifting arms each comprise: a kicker assembly extendablefrom one end of the indexing lifting arm toward the clamp support beam,the one end being closest to the clamp support beam so as to lift thetubular from the clamp support beam to the corresponding pipe storageoutrigger.
 6. The tubular supply apparatus of claim 4, wherein theindexing lifting arms each comprise: an indexing finger disposed at anend of the indexing lifting arm away from the transfer arm skid tosupport the tubular as the tubular is being lifted; and an indexing edgedisposed at the end of the indexing lifting arm away from the transferarm skid to queue a next tubular to be lifted on the pipe storageoutriggers.
 7. The tubular supply apparatus of claim 1, furthercomprising: a first actuator disposed between the lower link and thetransfer arm skid to control rotation of the lower link about the firstaxis; a second actuator disposed between the lower link and the upperlink to control rotation of the upper link about the second axis; and athird actuator disposed between the clamp support beam and the upperlink to control rotation of the clamp support beam about the third axis.8. The tubular supply apparatus of claim 7, wherein the first actuatorextends to raise the transfer arm to a generally vertical positionwithout changing states between a compression state and a tension state.9. The tubular supply apparatus of claim 7, wherein the second actuatorretracts to extend the distal end of the upper link to a side of thetransfer arm skid opposite the first axis.
 10. The tubular supplyapparatus of claim 7, wherein the third actuator extends as the secondactuator retracts to align the tubular with a well center drilling axis.11. The tubular supply apparatus of claim 7, further comprising: acontroller to control the first actuator to extend so as to raise thetransfer arm to a generally vertical position, to control the secondactuator to retract to extend the distal end of the upper link to a sideof the transfer arm skid opposite the first axis, and to control thethird actuator to retract to align the tubular with a well centerdrilling axis while the second actuator is controlled to retract. 12.The tubular supply apparatus of claim 11, wherein the second actuator iscontrolled to retract and the third actuator is controlled to extendafter the first actuator has extended to raise the transfer arm to thegenerally vertical position.
 13. A tubular supply apparatus to supply atubular to a drilling apparatus using a transfer arm to deliver thetubular with respect to the drilling apparatus, the tubular supplyapparatus comprising: a transfer arm skid; pivot blocks disposed at aside of the transfer arm skid; pipe storage outriggers rotatablyconnected to the pivot blocks to support the tubular thereon; andindexing lifting arms rotatably connected to the transfer arm skid tolift the tubular from the pipe storage outriggers to the transfer arm.14. The tubular supply apparatus of claim 13, wherein each of theindexing lifting arms comprises: an indexing finger disposed at an endthe indexing lifting arm to support the tubular as the tubular islifted.
 15. The tubular supply apparatus of claim 13, wherein each ofthe indexing lifting arms comprises: an indexing edge disposed at an endof the indexing lifting arm away from the transfer arm skid to queue anext tubular to be lifted on the pipe storage outriggers.
 16. Thetubular supply apparatus of claim 13, wherein each of the indexinglifting arms comprises: a kicker assembly extendable from one end of theindexing lifting arm toward the clamp support beam, the one end beingclosest to the transfer arm.
 17. A method of raising and lowering atransfer arm of a transfer arm skid to deliver a tubular to a wellcentered drill axis of a drilling apparatus, the method comprising:rotating a lower link, an upper link, and a clamp support beam of thetransfer arm about a first axis from a horizontal position to a verticalposition in which a center of gravity of the transfer arm is disposedabove the first axis; and rotating the upper link about a second axiswhile rotating the clamp support beam about a third axis from thevertical position toward the drilling apparatus while the lower linkremains in the vertical position.
 18. The method of claim 17, wherein:the rotating the lower link, the upper link, and the clamp support beamabout the first axis comprises extending a lower actuator connectedbetween the lower link of the transfer arm and the transfer arm skid toraise the transfer arm; and the rotating the upper link about the secondaxis while rotating the clamp support beam about the third axiscomprises aligning the tubular with the well center drill axis of thedrill string by compressing an upper actuator connected between theupper link of the transfer arm and the lower link while extending athird actuator connected between the upper link and the clamp supportbeam holding the tubular.
 19. The method of claim 18, wherein theextending of the lower actuator comprises: maintaining the loweractuator in a compression state while the lower actuator raises thetransfer arm.
 20. The method of claim 18, wherein the compressing of theupper actuator and the extending of the third actuator follows theextending of the lower actuator.